scholarly journals Column Extraction and Separation of Some Metal Ions by Diethylenetriamine Polysiloxane Immobilized Ligand System

2008 ◽  
Vol 5 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Nizam M. El-Ashgar
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Ph Value ◽  
Good Separation ◽  
Extraction And Separation ◽  
Ph Values ◽  
Ligand System ◽  
Chromatographic Parameters ◽  
Column Extraction ◽  
Optimum Separation

An extraction chromatographic solid porous polysiloxane functionalized by chelating diethylenetriamine ligand of the general formula P-(CH2)3-NH(CH2)2NH(CH2)2NH2, (Where P represents [Si-O]nsiloxane network) has been evaluated for the separation of Co(II), Ni(II) and Cu(II) from aqueous solutions. The chromatographic parameters of the separation method have been optimized. The ligand system retained Co(II), Cu(II) and Zn(II) effectively when used as a metal ion extractant by controlling the pH value. The ligand system also shows a good separation of a mixture of metal ions Co(II), Ni(II) and Cu(II) when used as chromatographic stationary phase. The optimum separation pH values were 4.5, 4 for Co(II) and Ni(II) respectively, while a solution of 0.1 M HNO3was used to elute Cu(II). Metal ions were also preconcentrated at pH 5.5. The chemisorbed metal ions were regenerated from the solid extractant using 0.5 M HCl.

scholarly journals Effective removal of heavy metal ions from aqueous solutions using a new chelating resin poly [2,5-(1,3,4-thiadiazole)-benzalimine]: kinetic and thermodynamic study

2015 ◽  
Vol 6 (2) ◽  
pp. 310-324 ◽  
Author(s):  
Selvaraj Dinesh Kirupha ◽  
Selvaraj Kalaivani ◽  
Thangaraj Vidhyadevi ◽  
Periyaraman Premkumar ◽  
Palanithamy Baskaralingam ◽  
...  
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Ph Value ◽  
Thermo Gravimetric Analysis ◽  
Kinetic Studies ◽  
Ion Concentration ◽  
Chelating Resin ◽  
Gravimetric Analysis ◽  
Equilibrium Data ◽  
Experimental Values

A novel poly [2,5-(1,3,4-thiadiazole)-benzalimine] abbreviated as TDPI adsorbent was synthesized using simple polycondensation technique. The synthetic route involves the preparation of 2,5-diamino-1,3,4-thiadiazole from 2,5-dithiourea and subsequent condensation with terephthalaldehyde. The resin was chemically characterized using Fourier transform infrared (FT-IR), 1H-NMR, and 13C-NMR spectroscopic analysis. Surface morphology and thermal stability were analyzed using scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA). The effect of the pH value of solution, contact time, adsorbent dose, and initial metal ion concentration were investigated by batch equilibrium adsorption experiments. Kinetic studies show that the adsorption of metal ions onto the resin proceeds according to the pseudo-second-order model and the equilibrium data were best interpreted by the Redlich–Peterson isotherm. The experimental values of the adsorption capacities of Pb2+, Cu2+, Ni2+, and Cd2+ on to TDPI could reach up to 437.2, 491.6, 493.7, and 481.9 mg.g−1 respectively. The exothermic nature of the process, the affinity of the adsorbent towards the metal ions and the feasibility of the process are explained in the thermodynamic parameters. The resin stability and re-usability studies suggest that the resin is chemically stable (0.3 N HCl and H2SO4) and could be regenerated without any serious decline in performance.

scholarly journals Multiple α-mannosidase activities in mammalian tissues as shown by metal-ion activation

1977 ◽  
Vol 163 (3) ◽  
pp. 557-564 ◽  
Author(s):  
S M Snaith
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Active Enzyme ◽  
Thiol Groups ◽  
Ion Activation ◽  
Ph Values ◽  
Neutral Ph ◽  
Mammalian Tissues ◽  
Different Types ◽  
Metal Ion Activation

1. Four different types of alpha-mannosidase activity were shown to occur in several tissues from the rat. There is the Zn2+-dependent enzyme, active at acidic pH, and three enzymes that are active near to neutral pH. 2. The ‘neutral’ enzymes are activated by Fe2+, Co2+ or Mn2+. 3. Optimum activities for these three enzymes are shown at pH values of 5.2, 6.5 and 7.3. The activity at pH6.5 is the only one evident without metal-ion activation, but activity is enhanced by all three metal ions. The activity at pH 5.2 is seen only in the presence of Fe2+ or Co2+, and the activity at pH7.3 is seen only in the presence of Co2+ or Mn2+ and in a non-chelating buffer medium. 4. The pH6.5-active enzyme is inactivated by EDTA, but activity is restored by excess of metal ion. 5. The enzymes differ markedly in their stability. The pH6.5-active enzyme is very labile and the pH7.3-active enzyme is the most stable. 6. Tissue preparations vary widely in their activity at pH6.5, but where activity is low it can be increased by incubation with one of the activating metal cations. 7. All the enzymes active at neutral pH are inhibited by heavy-metal ions and stabilized to some extent by thiol groups.

Removal of Pb(II), Zn(II), Sn(II) and Cu(II) Ions from Aqueous Solutions by Linear Alternating Poly(4,4'-biphenol oxalate) Oligomer

2020 ◽  
Vol 15 (2) ◽  
pp. 73-85
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Metal Ion ◽  
Ph Value ◽  
Equilibrium Concentration ◽  
Ion Uptake ◽  
Uptake Capacity ◽  
Concentration Data ◽  
Hno3 Solution ◽  
Metal Ion Uptake

Poly(4,4′-biphenol oxalate) oligomer was synthesized and characterized by FT-IR, elemental analysis XRD and thermal analysis. The capability of the oligomer to take away Pb(II), Zn(II), Sn(II) and Cu(II) metal ions from aqueous solutions was considered by the known batch and column techniques in terms of concentration, pH value, contact time and temperature. The results indicated that a high initial rate of metal-ion uptake by the oligomer was observed throughout the first 30 minutes, which enlarged slightly amid rising the pH value and then reached its greatest value at pH=5.00 for Pb(II) and Zn(II), pH=4.00 for Cu(II) and pH=6.00 for Sn(II). The oligomer exhibited a high metal-ion uptake capacity to Pb(II) and Zn(II), but a little metal-ion uptake capacity to Cu(II) and Sn(II). Linearized forms of the Langmuir, Freundlich and Dubinin–Radushkevich adsorption isotherms were used to investigate the experimental equilibrium concentration data of Pb(II), Zn(II), Cu(II) and Sn(II). ΔG values demonstrated that the adsorption process of these metal ions on the oligomer is favored while the ΔH values indicated that this process is endothermic. On the other hand, the entropy of the process is positive. In addition to batch experiments, column experiments were performed, where the metal ions were efficiently recovered by treatment of the metal-loaded oligomer with 1.0 M HNO3, 1.0 M HCl and 0.5 M EDTA. The best results were obtained with 1.0 M HNO3 solution.

scholarly journals Adsorption properties of a nanostructured hybrid material containing aluminium towards some metal ions

2011 ◽  
Vol 9 (5) ◽  
pp. 932-940 ◽  
Author(s):  
Albena Detcheva ◽  
Paunka Vassileva ◽  
Ralitsa Georgieva ◽  
Dimitrinka Voykova ◽  
Tsvetelina Gerganova ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Hybrid Material ◽  
Metal Ion ◽  
Ph Value ◽  
Sol Gel ◽  
Transition Metal Ions ◽  
Adsorption Properties ◽  
Adsorption Of Nitrogen ◽  
Pseudo Second Order

AbstractIn the present work the adsorption of some transition metal ions from aqueous solutions on a silica-based nanostructured hybrid material modified by aluminium was investigated. The novel organic-inorganic material was synthesized via a sol-gel method through hydrolysis and co-condensation reactions. Its structure was characterized by means of SEM, XRD and FTIR. Based on the data obtained the most probable cross-linking mechanism for the derived xerogel was proposed. The characterization of its texture parameters was carried out by low-temperature adsorption of nitrogen. The adsorption properties of this material with respect to Cu(II), Cr(III) and Pb(II) ions from single-component aqueous solutions and multi-component aqueous solutions containing also Cd(II) and Fe(III) were evaluated. The effect of contact time, acidity of initial solutions and metal ion concentrations was investigated using the batch method. Pseudo-first order, pseudo-second order and intraparticle diffusion models were used to analyze kinetic data. In all cases the adsorption was significantly affected by the pH value. Equilibrium modelling data were fitted to linear Langmuir, Freundlich and Dubinin-Radushkevich models. Best fit was observed for Langmuir model, which showed determination coefficients greater than 0.992 for all ions studied. The maximum adsorption capacities for single- and multi-component adsorption were calculated.

scholarly journals Production of activated carbon from poultry feathers for waste water treatment

2019 ◽  
Vol 80 (8) ◽  
pp. 1407-1412 ◽  
Author(s):  
Rue Chiramba ◽  
Gratitude Charis ◽  
Nonhlanhla Fungura ◽  
Gwiranai Danha ◽  
Tirivaviri Mamvura
Keyword(s):  
Waste Water ◽  
Heavy Metal ◽  
Activated Carbon ◽  
Metal Ions ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Ph Value ◽  
Waste Water Treatment ◽  
Limiting Factors ◽  
Poultry Feathers

Abstract Contamination of water bodies by heavy metal ions is a challenge many developing nations like Zimbabwe face, with negative environmental and socio-economic repercussions. Treating affected bodies usually requires a costly consignment of chemicals and activated carbon. This research investigates the possible use of an abundant waste resource – poultry feathers – to make activated carbon for heavy metal ion removal. Poultry consumption in this nation generates more than five million tonnes of feathers a year, with very few uses of this by-product. This research was carried out to evaluate the effectiveness of activated carbon synthesized from poultry feathers with sodium hydroxide as the activating agent. It was tested for removing heavy metal ions from waste water at Lake Chivero and the experimental work done showed that it had a removal efficiency as high as 97%, with a high affinity for lead ions as compared with chromium ions. Upon characterization, the activated carbon showed an iodine number of 520 mg and it worked best at a pH value of 8. The efficiency removal also increased with increasing adsorbent concentration as well as contact time up to a period where these factors ceased to be the limiting factors of the reaction.

Study on Properties of PG Separated and Purified from Actinidia arguta

2013 ◽  
Vol 850-851 ◽  
pp. 1197-1201
Author(s):  
Shu Qian Li ◽  
Chang Jiang Liu ◽  
Guang Xin ◽  
Bo Zhang
Keyword(s):  
Metal Ions ◽  
Ph Value ◽  
Michaelis Constant ◽  
Actinidia Arguta ◽  
Ph Values ◽  
Key Enzyme ◽  
Optimal Reaction Temperature ◽  
The Stability ◽  
Thermo Stability ◽  
Optimal Reaction

Polygalacturonase (PG) is key enzyme for softening consenescence mechanism of fruits. In this work, Properties of PG separated and purified from wildActinidia Argutawere studied. The result shows that the optimal reaction temperature is 40°C with a high enzyme activity around 30-50°C. PG keeps a thermo stability at the temperature ranging from 30-40°C, which decreases with increasing of temperature and PG will lose all its activity under 60-70°C for 1h. The optimal reaction pH value for this enzyme is 5.5. As far as the stability in different pH values is concerned, PG is relatively stable for preservation at pH4.5-6.5.The michaelis constant for PG is 27.31. When the concentration for EDTA is higher than 2mmol/L, it is inhibitive for PG . The metal ions of K+, Ca2+, Fe2+, Fe3+, Mg2+can activate the PG enzyme to some extent, the strength of activation:Mg2+Fe3+K+Fe2+Ca2+;The metal ions of Cu2+Zn2+Mn2+Ba2+Al3+can inhibit PG enzyme to some extent, the strength of inhibition:Al3+Ba2+Mn2+Cu2+Zn2+.

The sorption of lead and cadmium species by clay minerals

1977 ◽  
Vol 30 (7) ◽  
pp. 1417 ◽  
Author(s):  
H Farrah ◽  
WF Pickering
Keyword(s):  
Metal Ion ◽  
Ph Value ◽  
Cadmium Ions ◽  
Ph Values ◽  
Metal Ion Adsorption ◽  
Lead And Cadmium ◽  
Anionic Complexes ◽  
The Stability ◽  
Protonated Ligand ◽  
Ligand Species

The effect of pH changes and the presence of ligands on the uptake of lead and cadmium ions by three types of clay mineral (kaolinite, illite and montmorillonite) has been investigated. ��� In the absence of ligands, metal ion adsorption increases gradually with increasing pH until a threshold pH value is exceeded, whereupon total precipitation/sorption (attributed to formation of hydroxy species) occurs. With ligands present, the threshold point tends to shift to higher pH values, the magnitude of the effect depending on the stability of the metal complex formed. Adsorption of cationic metal complexes is subject to competition from charged protonated ligand species; anionic complexes are not sorbed.

Study on the Effect of Amphoteric Bagasse Hemicellulose on Heavy Metal Adsorption

2011 ◽  
Vol 399-401 ◽  
pp. 1282-1288 ◽  
Author(s):  
Li Jun Wang ◽  
Xin Liang Liu ◽  
Meng Ling Weng ◽  
Shuang Xi Li ◽  
Fu Sheng Wu ◽  
...  
Keyword(s):  
Linear Model ◽  
Metal Ion ◽  
Ph Value ◽  
Absorption Capacity ◽  
Heavy Metal Adsorption ◽  
Adsorption Dynamics ◽  
Adsorption Time ◽  
Initial Concentration ◽  
Ph Values ◽  
Pseudo Second Order

In this paper, ions i.e. Cu2+, Pb2+and Cd2+ were absorbed by the amphoteric bagasse hemicelluloses, and the influences of pH value, adsorption time and the initial concentration of metal ion have been studied. The results show that the optimal adsorption pH values for Cu2+, Pb2+ and Cd2+ are 6.5, 6.0 and 7.5, respectively. The adsorption capacity to ions Cu2+, Pb2+ and Cd2+ reaches the maximum values when the adsorption time is 180 min. Net adsorption to ions Cu2+, Pb2+ and Cd2+ increases with increasing the initial concentration of the metal ions. Analysis results of adsorption dynamics show that the adsorption of Cu2+, Pb2+ and Cd2+ follows Ho 's Pseudo second-order kinetics linear model. It can be seen from the adsorption isothermal research that absorption of the amphoteric bagasse hemicelluloses to ions Cu2+, Pb2+and Cd2+ can be well described by the Langmuir isotherm linear model. Moreover, the theoretical values of the maximum absorption capacity qmax for ions Cu2+, Pb2+ and Cd2+ were determined to be 21.98 mg/g, 81.97 mg/g and 31.85 mg/g, respectively.

Study on the Adsorption of Mixed Cd(II) and Pb(II) Ions by N,O-Carboxymethyl-Chitosan

2011 ◽  
Vol 236-238 ◽  
pp. 2523-2528
Author(s):  
Shan Shan Cheng ◽  
Chao Hua Zhang ◽  
Xi Hong Yang ◽  
Wan Cui Xie
Keyword(s):  
Metal Ions ◽  
Adsorption Capacity ◽  
Metal Ion ◽  
Ph Value ◽  
Carboxymethyl Chitosan ◽  
Effect Of Temperature ◽  
Mixed Solution ◽  
Isotherm Equation ◽  
Mixed Aqueous Solution ◽  
Langmuir Isotherm Equation

TheN,O-carboxymethyl-chitosan (N,O-CMC) was used to investigate the adsorptions of two metals of Cd(Ⅱ) and Pb(Ⅱ) ions in an mixed aqueous solution. The effects on adsorption capacities such as pH value, temperature, adsorbent dose and initial metal ion concentrations were investigated, and the dialysis method was applied to separate the materials after adsorption. The results revealed that the better adsorption ofN,O-CMC for Cd(Ⅱ) and Pb(Ⅱ) ions at the pH 7-8; the effect of temperature on the adsorption was not significant; the absorption of Cd(Ⅱ) and Pb(Ⅱ) ions was enhanced with the increase ofN,O-CMC amount; the adsorption capacity increasesed with the addition of the concentration of initial metal ions in the aqueous phase. The adsorption of Pb(Ⅱ) ion in Cd-Pb mixed solution on theN,O-CMC was well followed as the Langmuir isotherm equation under the concentration range studied, and Cd(Ⅱ) ion was corresponding to Langmuir adsorption equation in 100-200 mg/L and 200-500 mg/L, respectively. Conclusion:N,O-CMC was suitable for adsorbent to removal Cd(Ⅱ) and Pb(Ⅱ) ions, but it can selectively adsorption ions from the mixed solution, the adsorption capacity (Qm) for two metal ions was as follows: Pb(Ⅱ) > Cd(Ⅱ).

scholarly journals Using amine-functionalized magnetite hollow nanospheres (AMHNs) as adsorbents for heavy metal ions

2017 ◽  
Vol 76 (2) ◽  
pp. 452-458 ◽  
Author(s):  
Sen Lin ◽  
Lili Liu ◽  
Yong Yang ◽  
Wei Zhang ◽  
Meng Xu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Ph Value ◽  
Hollow Nanospheres ◽  
One Pot ◽  
Amine Functionalized ◽  
Physicochemical Features ◽  
Kinetics And Isotherms

In this paper, the amine-functionalized magnetite hollow nanospheres (AMHNs), prepared through a facile one-pot synthesis, were used as heavy metal ion adsorbents, whose morphology and physicochemical features were exploring by transmission electron microscopy, vibrating sample magnetometer, X-ray diffraction and Fourier-transform infrared analyses. Its adsorption performances for Pb2+, Cu2+, Zn2+, Ni2+ and Cd2+ were studied in detail. The adsorption increased with the increase of initial pH value of the solution and could be obviously affected by ionic strength. Also, the adsorption kinetics and isotherms were studied. The adsorption processes for Pb2+, Cu2+, Zn2+, Ni2+ and Cd2+ could all reach equilibrium in 60 min and be described well by the Langmuir thermodynamics model. The saturated adsorption capacities for Pb2+, Cu2+, Zn2+, Ni2+ and Cd2+ were 0.66, 0.47, 0.45, 0.38 and 0.26 mmol/g, respectively. In addition, the competitive adsorption showed the AMHNs had higher affinity to Pb2+ than to other heavy metal ions.

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